The invention relates to an injection mold for producing, from thermoplastic plastic, fittings or the like, which have at least one annular groove on the inside. The injection mold includes an outer mold which is divided into a first and second mold half and along a parting plane, and a mold core which is axially displaceable along the first mold half of the outer mold and on which there is formed, for forming the annular groove, a complementary mold bead consisting of ring segments carried by levers. The injection mold also includes an actuating element for swivelling the levers being disposed in an axially displaceable manner in the mold core, and a slider, which bridges the parting plane of the outer mold, being connected to the second mold half and having guide grooves, of differing obliqueness, and having engaged therewith motionally lateral projections both of the mold core and of the actuating element, said projections being disposed on the parting plane.
In EP 548 823 A it is disclosed that the extraction and insertion of the mold core is motionally coupled to the opening and closing of the outer mold. Provided for this purpose there is a slider which bridges the parting plane of the outer mold and has two lateral plates comprising guide grooves engaged with projections of the mold core and the actuating element.
In order to extend the opening stroke, an embodiment makes provision whereby the guide grooves are formed in a telescopically extensible element.
According to DE 94 15 523 U, which discloses an injection mold of the type stated at the outset, the actuating element for prior swivelling of the levers of the mold bead is also included in the motional coupling between the slider and the mold core.
Since, in the closed position, the greatest forces have to be introduced into the mold core at the start of the opening stroke, the projections are disposed on both sides in an axial plane of the fitting to be demolded, in which the parting plane of the outer mold is located. This arrangement ensures an axial introduction of force from the slider moving perpendicular to said parting plane. These projections, at the end of the opening stroke, are located at the end of the guide slots. The extent of the slider is limited in its direction of motion by the maximum possible extent of the overlap over the parting plane when the mold is in the closed position.